Friday, December 9, 2011

A polar bear drags the corpse of a tiny polar bear cub that it has caught and killled. Bears usually hunt seals, but will attack and eat their own kind

They are known to be ruthless killers. But this scene proves polar bears will even attack and eat their own kind, even if it's a defenceless cub.

Photographer Jenny Ross captured the shocking images and at first thought the bear was eating a seal as she approached by boat.

There was another polar bear nearby, and Ross believes that this could have been the cub's mother.

Cannibalism is not unknown in polar bears - but scientists have recently observed that the behaviour is on the increase among the animals

Shockingly, this behaviour is becoming increasingly common among the bears, according to Ross's research.

'As soon as the adult male became aware that a boat was approaching him, he basically stood to attention - he straddled the young bear's body, asserting control over it and conveying 'this is my food,' said Ross.

Ross said that the bear stood up defensively as she approached - and draggged its tiny victim to another ice floe to ensure it could continue enjoying its meal

'He then picked up the bear in his jaws and, just using the power of his jaws and his neck, transported it from one floe to another. And eventually, when he was a considerable distance away, he stopped and fed on the carcass.'

As Ross approached, the bear stood up 'to assert dominance' over the carcass - and warn her off from stealing the bear's 'meal'

It's been known that polar bears do kill - and sometimes eat - their own kind for some time. But the behaviour appears to be on the increase.

Ross's research is published in a paper in the journal Arctic, 'During breakup and melting in summer, the area of sea ice around the Svalbard Archipelago declines to a fraction of the winter total, and in many areas it disappears completely.'

'As the area of sea ice that polar bears can use for hunting declines, progressively fewer seals are accessible to the bears, and therefore the bears' hunting success likely declines as well.'

'Thus, at this time of year, young polar bears may represent a possible food source for adult males. As the climate continues to warm in the Arctic and the sea ice melts earlier in the summer, the frequency of such intraspecific predation may increase.'

'Predating another bear is a way to get food; it's probably a relatively easy way for a big adult male. And it seems that because of the circumstances of the loss of sea ice - that kind of behaviour may be becoming more common,' says Ross

'On land, they're looking for human garbage and human foods; they're starting to prey on seabirds and their eggs,' Ross told the BBC. 'None of those alternative foods can support them.'

Pictured in the Barents Sea, Svalbard Archipelago, it's the first known photo of polar bear cannibalism on the sea ice

As Ross's boat approached, the bear dragged the carcass away

Polar bears are known to be violent - and occasionally cannibalistic - but scientists believe this behaviour is increasing as their habitat comes under threat

'Predating another bear is a way to get food; it's probably a relatively easy way for a big adult male. And it seems that because of the circumstances of the loss of sea ice - that kind of behaviour may be becoming more common.'